In this research the mechanisms of several O2 oxidoreductases are being investigated. Two enzymes currently being intensively studied are inositol oxygenase and diamine oxidase. Also, since the activity of inositol oxygenase is modified by quinolinic acid, some aspects of quinolinic acid biosynthesis, especially its nonenzymic formation from alpha-amino-beta-carboxymuconic semialdehyde, are being studied. In other research, the role of thiazoline-2-carboxylate and glyoxylate, the products of the suspected physiological reactions catalyzed by D-amino acid oxidase, in controlling the activity of various enzymes is being investigated.